What license should I have?

You should continue to maintain your Home improvement contractor's license. Depending on how the initial contract is structured, you might be considered a "home improvement contractor" when you are doing your work. Do you typically work as a subcontractor for a general contractor when you are working on these homes?

Thanks for the reply Lawrence. 

Typically I am contracted by the homeowner for the work. 

Contractually I am not concerned. It is what the state of NJ view would be. The NJ DCA site does state that the HIC registration is not for new construction, so I am unsure as to where this work actually falls in that regard. 

I’m happy to respond to your question. You must register under the New Jersey New Home Warranty and Builders’ Registration Act, N.J.S.A. sec. 46:3B-1, et seq.

Here (by links) is your answer, procedure and form in full detail:

https://www.state.nj.us/dca/divisions/codes/forms/pdf_nhw/nhwprenew.pdf

https://www.nj.gov/dca/divisions/codes/offices/nhw_for_builders.html

As other questions, issues or needs arise, you are welcome to call me at (914)412-7261 direct with voicemail or email to tcamp@maringoodman.com. I am based in Berkeley Heights, NJ and have been in practice for over three decades.

Addendum: The Anonymous Contractor has since contacted me directly, offered additional comments, and we are pursuing verification with the Division of Consumer Affairs, to which I have submitted inquiry.

[test, as I'm having problems posting follow-up answer]

 I actually reached out to the Department of Community Affairs
on this since the contractor was being challenged for having only a Home
Improvement Contractor license. The Bureau Chief for Homeowner Protection at
the Department was kind enough to get back to me in less than a day. Mr. Fahy
there confirms that the carpenter working as a subcontractor for a general
contractor new home builder need not be registered himself as a New Home
Builder. I would add that the subcontractor, if organized as a business, should
be registered to do business with the Department of Treasury in NJ. And the
subcontractor should also contact the local municipality - either the Town
Clerk or the Construction Official - to see if there are any local requirements.
But Mr. Fahy appears to clear up the State-level issue, here [all that follows
from his email to me]: 

From: Fahy, Jim [DCA] Jim.Fahy@dca.nj.gov Sent: Tuesday,
March 28, 2023 12:01 PM To: Terence W. Camp tcamp@maringoodman.com

Subject:
New Home construction question  

Terence W. Camp,  

The carpenter working as a subcontractor for the
GC does not have to be a registered new home builder since the
carpenter/subcontractor will not be providing the new home warranty.  

All builders of new homes, including single
family, townhouse, duplex (two-family), cooperative, condominium,
factory-built, and modular residences are required to register with the New
Home Warranty Program. A builder is any individual or organization in the
business of constructing new homes, including anyone who constructs a new home
for sale, acts as prime contractor to construct a new home for himself/herself
or for another person, contracts with a general contractor for construction of
a new home, or sells or transfers title to land and then participates in the
construction of a new home. It does not include a person who constructs a new
home for his/her own personal use, a licensed architect, engineer, or attorney,
or someone who contracts with a licensed architect, engineer, or attorney to
provide professional services related to the construction of a new home.  

Additional information about the New Home Builder
Registration and New Home Warranty for Builders can be found at:  

NJ
Department of Community Affairs

Jim Fahy  

James F. Fahy  

Bureau Chief  

Department of Community Affairs  

Bureau of Homeowner Protection  

609-984-7905